// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_D8_H_
#define V8_D8_H_

#include <iterator>
#include <map>
#include <memory>
#include <queue>
#include <string>
#include <unordered_map>
#include <vector>

#include "src/allocation.h"
#include "src/async-hooks-wrapper.h"
#include "src/base/platform/time.h"
#include "src/string-hasher.h"
#include "src/utils.h"

#include "src/base/once.h"

namespace v8 {

// A single counter in a counter collection.
class Counter {
public:
    static const int kMaxNameSize = 64;
    int32_t* Bind(const char* name, bool histogram);
    int32_t* ptr() { return &count_; }
    int32_t count() { return count_; }
    int32_t sample_total() { return sample_total_; }
    bool is_histogram() { return is_histogram_; }
    void AddSample(int32_t sample);

private:
    int32_t count_;
    int32_t sample_total_;
    bool is_histogram_;
    uint8_t name_[kMaxNameSize];
};

// A set of counters and associated information.  An instance of this
// class is stored directly in the memory-mapped counters file if
// the --map-counters options is used
class CounterCollection {
public:
    CounterCollection();
    Counter* GetNextCounter();

private:
    static const unsigned kMaxCounters = 512;
    uint32_t magic_number_;
    uint32_t max_counters_;
    uint32_t max_name_size_;
    uint32_t counters_in_use_;
    Counter counters_[kMaxCounters];
};

typedef std::unordered_map<std::string, Counter*> CounterMap;

class SourceGroup {
public:
    SourceGroup()
        : next_semaphore_(0)
        , done_semaphore_(0)
        , thread_(nullptr)
        , argv_(nullptr)
        , begin_offset_(0)
        , end_offset_(0)
    {
    }

    ~SourceGroup();

    void Begin(char** argv, int offset)
    {
        argv_ = const_cast<const char**>(argv);
        begin_offset_ = offset;
    }

    void End(int offset) { end_offset_ = offset; }

    // Returns true on success, false if an uncaught exception was thrown.
    bool Execute(Isolate* isolate);

    void StartExecuteInThread();
    void WaitForThread();
    void JoinThread();

private:
    class IsolateThread : public base::Thread {
    public:
        explicit IsolateThread(SourceGroup* group);

        void Run() override { group_->ExecuteInThread(); }

    private:
        SourceGroup* group_;
    };

    void ExecuteInThread();

    base::Semaphore next_semaphore_;
    base::Semaphore done_semaphore_;
    base::Thread* thread_;

    void ExitShell(int exit_code);
    Local<String> ReadFile(Isolate* isolate, const char* name);

    const char** argv_;
    int begin_offset_;
    int end_offset_;
};

// The backing store of an ArrayBuffer or SharedArrayBuffer, after
// Externalize() has been called on it.
class ExternalizedContents {
public:
    explicit ExternalizedContents(const ArrayBuffer::Contents& contents)
        : data_(contents.Data())
        , length_(contents.ByteLength())
        , deleter_(contents.Deleter())
        , deleter_data_(contents.DeleterData())
    {
    }
    explicit ExternalizedContents(const SharedArrayBuffer::Contents& contents)
        : data_(contents.Data())
        , length_(contents.ByteLength())
        , deleter_(contents.Deleter())
        , deleter_data_(contents.DeleterData())
    {
    }
    ExternalizedContents(ExternalizedContents&& other) V8_NOEXCEPT
        : data_(other.data_),
          length_(other.length_),
          deleter_(other.deleter_),
          deleter_data_(other.deleter_data_)
    {
        other.data_ = nullptr;
        other.length_ = 0;
        other.deleter_ = nullptr;
        other.deleter_data_ = nullptr;
    }
    ExternalizedContents& operator=(ExternalizedContents&& other) V8_NOEXCEPT
    {
        if (this != &other) {
            data_ = other.data_;
            length_ = other.length_;
            deleter_ = other.deleter_;
            deleter_data_ = other.deleter_data_;
            other.data_ = nullptr;
            other.length_ = 0;
            other.deleter_ = nullptr;
            other.deleter_data_ = nullptr;
        }
        return *this;
    }
    ~ExternalizedContents();

private:
    void* data_;
    size_t length_;
    ArrayBuffer::Contents::DeleterCallback deleter_;
    void* deleter_data_;

    DISALLOW_COPY_AND_ASSIGN(ExternalizedContents);
};

class SerializationData {
public:
    SerializationData()
        : size_(0)
    {
    }

    uint8_t* data() { return data_.get(); }
    size_t size() { return size_; }
    const std::vector<ArrayBuffer::Contents>& array_buffer_contents()
    {
        return array_buffer_contents_;
    }
    const std::vector<SharedArrayBuffer::Contents>&
    shared_array_buffer_contents()
    {
        return shared_array_buffer_contents_;
    }
    const std::vector<WasmModuleObject::TransferrableModule>&
    transferrable_modules()
    {
        return transferrable_modules_;
    }

private:
    struct DataDeleter {
        void operator()(uint8_t* p) const { free(p); }
    };

    std::unique_ptr<uint8_t, DataDeleter> data_;
    size_t size_;
    std::vector<ArrayBuffer::Contents> array_buffer_contents_;
    std::vector<SharedArrayBuffer::Contents> shared_array_buffer_contents_;
    std::vector<WasmModuleObject::TransferrableModule> transferrable_modules_;

private:
    friend class Serializer;

    DISALLOW_COPY_AND_ASSIGN(SerializationData);
};

class SerializationDataQueue {
public:
    void Enqueue(std::unique_ptr<SerializationData> data);
    bool Dequeue(std::unique_ptr<SerializationData>* data);
    bool IsEmpty();
    void Clear();

private:
    base::Mutex mutex_;
    std::vector<std::unique_ptr<SerializationData>> data_;
};

class Worker {
public:
    Worker();
    ~Worker();

    // Run the given script on this Worker. This function should only be called
    // once, and should only be called by the thread that created the Worker.
    void StartExecuteInThread(const char* script);
    // Post a message to the worker's incoming message queue. The worker will
    // take ownership of the SerializationData.
    // This function should only be called by the thread that created the Worker.
    void PostMessage(std::unique_ptr<SerializationData> data);
    // Synchronously retrieve messages from the worker's outgoing message queue.
    // If there is no message in the queue, block until a message is available.
    // If there are no messages in the queue and the worker is no longer running,
    // return nullptr.
    // This function should only be called by the thread that created the Worker.
    std::unique_ptr<SerializationData> GetMessage();
    // Terminate the worker's event loop. Messages from the worker that have been
    // queued can still be read via GetMessage().
    // This function can be called by any thread.
    void Terminate();
    // Terminate and join the thread.
    // This function can be called by any thread.
    void WaitForThread();

private:
    class WorkerThread : public base::Thread {
    public:
        explicit WorkerThread(Worker* worker)
            : base::Thread(base::Thread::Options("WorkerThread"))
            , worker_(worker)
        {
        }

        void Run() override { worker_->ExecuteInThread(); }

    private:
        Worker* worker_;
    };

    void ExecuteInThread();
    static void PostMessageOut(const v8::FunctionCallbackInfo<v8::Value>& args);

    base::Semaphore in_semaphore_;
    base::Semaphore out_semaphore_;
    SerializationDataQueue in_queue_;
    SerializationDataQueue out_queue_;
    base::Thread* thread_;
    char* script_;
    base::Atomic32 running_;
};

class PerIsolateData {
public:
    explicit PerIsolateData(Isolate* isolate);

    ~PerIsolateData();

    inline static PerIsolateData* Get(Isolate* isolate)
    {
        return reinterpret_cast<PerIsolateData*>(isolate->GetData(0));
    }

    class RealmScope {
    public:
        explicit RealmScope(PerIsolateData* data);
        ~RealmScope();

    private:
        PerIsolateData* data_;
    };

    inline void SetTimeout(Local<Function> callback, Local<Context> context);
    inline MaybeLocal<Function> GetTimeoutCallback();
    inline MaybeLocal<Context> GetTimeoutContext();

    AsyncHooks* GetAsyncHooks() { return async_hooks_wrapper_; }

private:
    friend class Shell;
    friend class RealmScope;
    Isolate* isolate_;
    int realm_count_;
    int realm_current_;
    int realm_switch_;
    Global<Context>* realms_;
    Global<Value> realm_shared_;
    std::queue<Global<Function>> set_timeout_callbacks_;
    std::queue<Global<Context>> set_timeout_contexts_;
    AsyncHooks* async_hooks_wrapper_;

    int RealmIndexOrThrow(const v8::FunctionCallbackInfo<v8::Value>& args,
        int arg_offset);
    int RealmFind(Local<Context> context);
};

class ShellOptions {
public:
    enum CodeCacheOptions {
        kNoProduceCache,
        kProduceCache,
        kProduceCacheAfterExecute
    };

    ShellOptions()
        : send_idle_notification(false)
        , invoke_weak_callbacks(false)
        , omit_quit(false)
        , wait_for_wasm(true)
        , stress_opt(false)
        , stress_deopt(false)
        , stress_runs(1)
        , interactive_shell(false)
        , test_shell(false)
        , expected_to_throw(false)
        , mock_arraybuffer_allocator(false)
        , enable_inspector(false)
        , num_isolates(1)
        , compile_options(v8::ScriptCompiler::kNoCompileOptions)
        , stress_background_compile(false)
        , code_cache_options(CodeCacheOptions::kNoProduceCache)
        , isolate_sources(nullptr)
        , icu_data_file(nullptr)
        , icu_locale(nullptr)
        , natives_blob(nullptr)
        , snapshot_blob(nullptr)
        , trace_enabled(false)
        , trace_path(nullptr)
        , trace_config(nullptr)
        , lcov_file(nullptr)
        , disable_in_process_stack_traces(false)
        , read_from_tcp_port(-1)
    {
    }

    ~ShellOptions()
    {
        delete[] isolate_sources;
    }

    bool send_idle_notification;
    bool invoke_weak_callbacks;
    bool omit_quit;
    bool wait_for_wasm;
    bool stress_opt;
    bool stress_deopt;
    int stress_runs;
    bool interactive_shell;
    bool test_shell;
    bool expected_to_throw;
    bool mock_arraybuffer_allocator;
    size_t mock_arraybuffer_allocator_limit = 0;
    bool enable_inspector;
    int num_isolates;
    v8::ScriptCompiler::CompileOptions compile_options;
    bool stress_background_compile;
    CodeCacheOptions code_cache_options;
    SourceGroup* isolate_sources;
    const char* icu_data_file;
    const char* icu_locale;
    const char* natives_blob;
    const char* snapshot_blob;
    bool trace_enabled;
    const char* trace_path;
    const char* trace_config;
    const char* lcov_file;
    bool disable_in_process_stack_traces;
    int read_from_tcp_port;
    bool enable_os_system = false;
    bool quiet_load = false;
    int thread_pool_size = 0;
    bool stress_delay_tasks = false;
    std::vector<const char*> arguments;
    bool include_arguments = true;
};

class Shell : public i::AllStatic {
public:
    enum PrintResult : bool { kPrintResult = true,
        kNoPrintResult = false };
    enum ReportExceptions : bool {
        kReportExceptions = true,
        kNoReportExceptions = false
    };
    enum ProcessMessageQueue : bool {
        kProcessMessageQueue = true,
        kNoProcessMessageQueue = false
    };

    static bool ExecuteString(Isolate* isolate, Local<String> source,
        Local<Value> name, PrintResult print_result,
        ReportExceptions report_exceptions,
        ProcessMessageQueue process_message_queue);
    static bool ExecuteModule(Isolate* isolate, const char* file_name);
    static void ReportException(Isolate* isolate, TryCatch* try_catch);
    static Local<String> ReadFile(Isolate* isolate, const char* name);
    static Local<Context> CreateEvaluationContext(Isolate* isolate);
    static int RunMain(Isolate* isolate, int argc, char* argv[], bool last_run);
    static int Main(int argc, char* argv[]);
    static void Exit(int exit_code);
    static void OnExit(Isolate* isolate);
    static void CollectGarbage(Isolate* isolate);
    static bool EmptyMessageQueues(Isolate* isolate);
    static bool CompleteMessageLoop(Isolate* isolate);

    static std::unique_ptr<SerializationData> SerializeValue(
        Isolate* isolate, Local<Value> value, Local<Value> transfer);
    static MaybeLocal<Value> DeserializeValue(
        Isolate* isolate, std::unique_ptr<SerializationData> data);
    static void CleanupWorkers();
    static int* LookupCounter(const char* name);
    static void* CreateHistogram(const char* name,
        int min,
        int max,
        size_t buckets);
    static void AddHistogramSample(void* histogram, int sample);
    static void MapCounters(v8::Isolate* isolate, const char* name);

    static void PerformanceNow(const v8::FunctionCallbackInfo<v8::Value>& args);

    static void RealmCurrent(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RealmOwner(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RealmGlobal(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RealmCreate(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RealmNavigate(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RealmCreateAllowCrossRealmAccess(
        const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RealmDetachGlobal(
        const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RealmDispose(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RealmSwitch(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RealmEval(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RealmSharedGet(Local<String> property,
        const PropertyCallbackInfo<Value>& info);
    static void RealmSharedSet(Local<String> property,
        Local<Value> value,
        const PropertyCallbackInfo<void>& info);

    static void AsyncHooksCreateHook(
        const v8::FunctionCallbackInfo<v8::Value>& args);
    static void AsyncHooksExecutionAsyncId(
        const v8::FunctionCallbackInfo<v8::Value>& args);
    static void AsyncHooksTriggerAsyncId(
        const v8::FunctionCallbackInfo<v8::Value>& args);

    static void Print(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void PrintErr(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void Write(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void WaitUntilDone(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void NotifyDone(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void QuitOnce(v8::FunctionCallbackInfo<v8::Value>* args);
    static void Quit(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void Version(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void Read(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void ReadBuffer(const v8::FunctionCallbackInfo<v8::Value>& args);
    static Local<String> ReadFromStdin(Isolate* isolate);
    static void ReadLine(const v8::FunctionCallbackInfo<v8::Value>& args)
    {
        args.GetReturnValue().Set(ReadFromStdin(args.GetIsolate()));
    }
    static void Load(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void SetTimeout(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void WorkerPostMessage(
        const v8::FunctionCallbackInfo<v8::Value>& args);
    static void WorkerGetMessage(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void WorkerTerminate(const v8::FunctionCallbackInfo<v8::Value>& args);
    // The OS object on the global object contains methods for performing
    // operating system calls:
    //
    // os.system("program_name", ["arg1", "arg2", ...], timeout1, timeout2) will
    // run the command, passing the arguments to the program.  The standard output
    // of the program will be picked up and returned as a multiline string.  If
    // timeout1 is present then it should be a number.  -1 indicates no timeout
    // and a positive number is used as a timeout in milliseconds that limits the
    // time spent waiting between receiving output characters from the program.
    // timeout2, if present, should be a number indicating the limit in
    // milliseconds on the total running time of the program.  Exceptions are
    // thrown on timeouts or other errors or if the exit status of the program
    // indicates an error.
    //
    // os.chdir(dir) changes directory to the given directory.  Throws an
    // exception/ on error.
    //
    // os.setenv(variable, value) sets an environment variable.  Repeated calls to
    // this method leak memory due to the API of setenv in the standard C library.
    //
    // os.umask(alue) calls the umask system call and returns the old umask.
    //
    // os.mkdirp(name, mask) creates a directory.  The mask (if present) is anded
    // with the current umask.  Intermediate directories are created if necessary.
    // An exception is not thrown if the directory already exists.  Analogous to
    // the "mkdir -p" command.
    static void System(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void ChangeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void SetEnvironment(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void UnsetEnvironment(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void SetUMask(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void MakeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args);
    static void RemoveDirectory(const v8::FunctionCallbackInfo<v8::Value>& args);
    static MaybeLocal<Promise> HostImportModuleDynamically(
        Local<Context> context, Local<ScriptOrModule> referrer,
        Local<String> specifier);
    static void HostInitializeImportMetaObject(Local<Context> context,
        Local<Module> module,
        Local<Object> meta);

    // Data is of type DynamicImportData*. We use void* here to be able
    // to conform with MicrotaskCallback interface and enqueue this
    // function in the microtask queue.
    static void DoHostImportModuleDynamically(void* data);
    static void AddOSMethods(v8::Isolate* isolate,
        Local<ObjectTemplate> os_template);

    static const char* kPrompt;
    static ShellOptions options;
    static ArrayBuffer::Allocator* array_buffer_allocator;

    static void SetWaitUntilDone(Isolate* isolate, bool value);

    static char* ReadCharsFromTcpPort(const char* name, int* size_out);

    static void set_script_executed() { script_executed_.store(true); }
    static bool use_interactive_shell()
    {
        return (options.interactive_shell || !script_executed_.load()) && !options.test_shell;
    }

private:
    static Global<Context> evaluation_context_;
    static base::OnceType quit_once_;
    static Global<Function> stringify_function_;
    static const char* stringify_source_;
    static CounterMap* counter_map_;
    // We statically allocate a set of local counters to be used if we
    // don't want to store the stats in a memory-mapped file
    static CounterCollection local_counters_;
    static CounterCollection* counters_;
    static base::OS::MemoryMappedFile* counters_file_;
    static base::LazyMutex context_mutex_;
    static const base::TimeTicks kInitialTicks;

    static base::LazyMutex workers_mutex_; // Guards the following members.
    static bool allow_new_workers_;
    static std::vector<Worker*> workers_;
    static std::vector<ExternalizedContents> externalized_contents_;

    // Multiple isolates may update this flag concurrently.
    static std::atomic<bool> script_executed_;

    static void WriteIgnitionDispatchCountersFile(v8::Isolate* isolate);
    // Append LCOV coverage data to file.
    static void WriteLcovData(v8::Isolate* isolate, const char* file);
    static Counter* GetCounter(const char* name, bool is_histogram);
    static Local<String> Stringify(Isolate* isolate, Local<Value> value);
    static void Initialize(Isolate* isolate);
    static void RunShell(Isolate* isolate);
    static bool SetOptions(int argc, char* argv[]);
    static Local<ObjectTemplate> CreateGlobalTemplate(Isolate* isolate);
    static MaybeLocal<Context> CreateRealm(
        const v8::FunctionCallbackInfo<v8::Value>& args, int index,
        v8::MaybeLocal<Value> global_object);
    static void DisposeRealm(const v8::FunctionCallbackInfo<v8::Value>& args,
        int index);
    static MaybeLocal<Module> FetchModuleTree(v8::Local<v8::Context> context,
        const std::string& file_name);
    static ScriptCompiler::CachedData* LookupCodeCache(Isolate* isolate,
        Local<Value> name);
    static void StoreInCodeCache(Isolate* isolate, Local<Value> name,
        const ScriptCompiler::CachedData* data);
    // We may have multiple isolates running concurrently, so the access to
    // the isolate_status_ needs to be concurrency-safe.
    static base::LazyMutex isolate_status_lock_;
    static std::map<Isolate*, bool> isolate_status_;

    static base::LazyMutex cached_code_mutex_;
    static std::map<std::string, std::unique_ptr<ScriptCompiler::CachedData>>
        cached_code_map_;
};

} // namespace v8

#endif // V8_D8_H_
